Guen Young Lee

Diagnostic Yield of Fluoroscopy-Guided Biopsy for Infectious Spondylitis

BACKGROUND AND PURPOSE: CT is currently the method of choice for guiding biopsy of lesions of the spine. However, in our hospital, fluoroscopy-guided percutaneous biopsy has been preferred for several years because of equipment availability and easy craniocaudal angulation. The aim of this study was to evaluate the efficacy of fluoroscopy-guided percutaneous biopsy in a clinical setting for diagnosing infectious spondylitis. MATERIALS AND METHODS: A retrospective study was performed to evaluate 170 fluoroscopy-guided percutaneous biopsies in 140 patients (male/female = 70:70; mean age, 65.1 years; range, 16–89 years) in a clinical setting who were suspected of having infectious spondylitis between July 2003 and March 2010. Diagnosis was based on pathologic confirmation by tissue or culture from biopsy. The percentage of adequate specimens for diagnosis, histopathologic diagnosis for infectious spondylitis, and positive cultures for causative organisms were evaluated by retrospective review of medical records. RESULTS: Adequate specimens for diagnosis were obtained in 165 of 170 cases (97.1%). The diagnosis of infectious spondylitis resulted in 134 of 170 cases confirmed through histopathology or clinical outcome (78.8%). In 51 of 134 cases (38.1%), the causative organism was confirmed by specimens from percutaneous bone biopsy. There were no biopsy-related major complications. The most common organism isolated was Mycobacterium tuberculosis (24 cases), followed by Staphylococcus aureus, Streptococcus agalactiae, and Streptococcus viridans. CONCLUSIONS: Fluoroscopy-guided percutaneous biopsy is as accurate and effective as CT-guided biopsy for diagnosing infectious spondylitis.

Therapeutic Trial of Fluoroscopic Interlaminar Epidural Steroid Injection for Axial Low Back Pain: Effectiveness and Outcome Predictors

BACKGROUND AND PURPOSE: An ESI for managing LBP is one of the most commonly performed interventions. The purpose of this observational study was to assess the effect of a therapeutic trial of a fluoroscopic interlaminar ESI for axial LBP and to analyze the outcome predictors. MATERIALS AND METHODS: All patients who received an interlaminar ESI for axial LBP at our facility in 2007 and 2008 were included. Initial short-term follow-up was done at <1 month after ESI. ESI was considered effective if patients had a reduction of >50% in their pain scores. In July 2009, telephone interviews were conducted by using formatted questions including the NASS patient-satisfaction index. The symptom-free interval was computed by the Kaplan-Meier method. Outcome predictors such as age, sex, duration of LBP, and MR imaging findings were statistically analyzed by the Mann-Whitney U and the Fisher exact tests. RESULTS: Eighty-one patients (male/female = 16:65; mean age, 49.9 years; range, 17–77 years) were included in the study. The interlaminar ESI was effective in 63 of the 81 patients (77.8%) at initial short-term follow-up. For the 63 patients in whom ESI was effective, the median symptom-free interval was 154 days (95% CI, 96–212 days). Among 68 patients for whom telephone interviews were possible, 44 patients (64.7%) replied positively to the NASS patient satisfaction index (NASS patient-satisfaction index, 1 or 2). There were no significant outcome predictors. CONCLUSIONS: The therapeutic trial of a fluoroscopic interlaminar ESI was effective for axial LBP without significant outcome predictors.

MR Classification System Based on Axial Images for Cervical Compressive Myelopathy

PURPOSE To propose a new magnetic resonance (MR) classification system based on axial images for cervical compressive myelopathy (CCM) (Ax-CCM system), to assess the interobserver agreement with the Ax-CCM system, and to evaluate the relationship between Ax-CCM patterns and the baseline severity of CCM and the subsequent surgical outcome. MATERIALS AND METHODS The institutional review board approved this retrospective study. A total of 202 patients (male-to-female ratio, 128:84; mean age ± standard deviation, 56.3 years ± 11.9; age range, 24-83 years) with CCM who underwent preoperative MR imaging and decompression surgery were retrospectively evaluated. The Ax-CCM pattern was based on the margin and extent of intramedullary hyperintensity on axial T2-weighted images, as follows; type 0 = normal, type 1 = diffuse, type 2 = fuzzy focal, and type 3 = discrete focal. Interobserver variability was analyzed by using the intraclass correlation coefficient across three readers. The modified Japanese Orthopedic Association (JOA) score and the postoperative improvement (good vs little improvement) were evaluated according to the Ax-CCM pattern by using one-way analysis of variance, the χ(2) test, and the Fisher exact test. RESULTS The intraclass correlation coefficient for the Ax-CCM system was 0.83. The preoperative JOA score was significantly different according to Ax-CCM pattern across all readers (P < .05), with the type 2 pattern showing the worst preoperative JOA score (mean, 11.6 ± 3.1 for readers A and C and 11.7 ± 2.9 for reader B). The proportion of good improvement was significantly lower with the type 2 pattern (27 of 72 patients, 37%) than with the other patterns (64 of 123 patients, 52%) (P = .034). CONCLUSION The Ax-CCM system showed good interobserver agreement, and the type 2 pattern was correlated with poor preoperative neurologic status and less postoperative improvement.

Herniation of cartilaginous endplates in the lumbar spine: MRI findings.

OBJECTIVE The purpose of this study was to determine reliable MRI findings suggesting disk herniation with cartilage endplate herniation in the lumbar spine. MATERIALS AND METHODS The records of 73 patients who underwent lumbar spinal MRI and lumbar microdiskectomy between March 2005 and January 2009 were searched to find those with the diagnosis of disk herniation with cartilage endplate herniation confirmed during surgery. The following morphologic features were assessed: posterior corners (posterior marginal nodes, dorsal corner defects, Modic changes, and posterior osteophytes), mid endplates (endplate irregularities, Modic changes), and heterogeneous low signal intensity of extruded material. The chi-square test and multiple logistic regression analysis with age, body mass index, and sex as covariates were used for the analysis. The ROC curve was obtained with scores of the statistically significant MRI findings. RESULTS Posterior marginal nodes, posterior osteophytes, Modic changes in posterior corners, mid endplate irregularities, Modic changes in mid endplates, and heterogeneous low signal intensity of extruded material were significantly more frequent in patients with disk herniation with cartilage endplate herniation (0.000 < p < 0.009). The AUC for diagnosing disk herniation with cartilage endplate herniation with our scoring system of the six MRI findings (0-6) was 0.888. CONCLUSION The presence of disk herniation with cartilage endplate herniation could be ascertained with the following MRI findings: posterior marginal nodes, posterior osteophytes, mid endplate irregularities, heterogeneous low signal intensity of extruded material, and Modic changes in posterior corners and mid endplates.

Long-term assessment of clinical outcomes of ultrasound-guided steroid injections in patients with piriformis syndrome

Purpose: The purpose of this study was to evaluate the long-term efficacy of ultrasound (US)-guided steroid injections in patients with piriformis syndrome. Methods: Between January 2010 and October 2012, 63 patients (23 men and 40 women; average age, 63.2 years; range, 24 to 90 years) were diagnosed with piriformis syndrome based on clinical history, electromyography, and flexion-adduction-internal rotation test results. They were divided into two groups. The first group (37 subjects) received a US-guided steroid injection around the piriformis muscle. The second group (26 subjects) received both piriformis muscle and spinal epidural injections. The therapeutic effect was categorized as improvement, partial improvement, or failure depending on the degree of symptom alleviation one month after injection, based on a review of each patient’s medical records. Results: In the first group, 15 patients (40.5%) showed improvement, seven (18.9%) showed partial improvement, and 15 (40.5%) failed to respond to the initial treatment. In the second group, eight patients (30.8%) showed improvement, 11 (42.3%) showed partial improvement, and seven (26.9%) failed to respond to the initial treatment. A second piriformis injection was performed in four cases, after which two patients showed improvement within 3 years, but the other two showed no therapeutic effect. Conclusion: US-guided steroid injection may be an effective treatment option for patients with piriformis syndrome.

C2 nerve root on magnetic resonance imaging of occipital neuralgia.

Study Design. Review and grade the morphology of the C1–C2 neural foramina, from the MR images of patients who underwent C1–C2 spinal surgery, and determine the relationship with ON. Objective. To evaluate the feasibility of MRI for C1–C2 neural foramen evaluation with a new grading system and to correlate the C1–C2 neural foramen grade with ON. Summary of Background Data. There have been no MRI studies of patients with and without ON in relation to C2 nerve root ganglion findings. Methods. Among the registry of 124 patients who underwent C1–C2 spinal surgery between July 2004 and May 2012 in Seoul National University Bundang Hospital, we enrolled 101 patients who had information about ON and a relevant preoperative cervical spine MR image. A total of 202 neural foramina were evaluated with our new C1–C2 neural foramen grading system (grade, 0–3) using consensus reading by 2 experienced radiologists who were blinded to the clinical information. The relationship between the C1–C2 grading system and ON was assessed using a &khgr;2 test and Fisher exact test. Inter- and intraobserver reliability agreement was assessed using the &kgr; statistic. Results. All C1–C2 neural foramina were delineated on T2 parasagittal images. Among 202 C1–C2 neural foramina, grade zero was found in 49 foramina (24.3%), grade 1 in 95 (47.0%), grade 2 in 30 (14.9%), and grade 3 in 28 (13.9%). Grade 1 stenosis was most frequently noted. The grade 2 group had the most frequent prevalence of ON (43.3%), followed by grade 3 (35.7%), grade zero (30.6%), and grade 1 (29.5%). However, the relationship between the grade and ON was not statistically significant. Inter- and intraobserver agreements were substantially high. Conclusion. C1–C2 neural foramina can be depicted on MR image. However, the relationship between the new grading system for C1–C2 neural foramina and ON was not statistically significant. Level of Evidence: 4

Texture Analysis of Torn Rotator Cuff on Preoperative Magnetic Resonance Arthrography as a Predictor of Postoperative Tendon Status

Objective To evaluate texture data of the torn supraspinatus tendon (SST) on preoperative T2-weighted magnetic resonance arthrography (MRA) using the gray-level co-occurrence matrix (GLCM) for prediction of post-operative tendon state. Materials and Methods Fifty patients who underwent arthroscopic rotator cuff repair for full-thickness tears of the SST were included in this retrospective study. Based on 1-year follow-up, magnetic resonance imaging showed that 30 patients had intact SSTs, and 20 had rotator cuff retears. Using GLCM, two radiologists measured independantly the highest signal intensity area of the distal end of the torn SST on preoperative T2-weighted MRA, which were compared between two groups.The relationships with other well-known prognostic factors, including age, tear size (anteroposterior dimension), retraction size (mediolateral tear length), grade of fatty degeneration of the SST and infraspinatus tendon, and arthroscopic fixation technique (single or double row), also were evaluated. Results Of all the GLCM features, the retear group showed significantly higher entropy (p < 0.001 and p = 0.001), variance (p = 0.030 and 0.011), and contrast (p = 0.033 and 0.012), but lower angular second moment (p < 0.001 and p = 0.002) and inverse difference moment (p = 0.027 and 0.027), as well as larger tear size (p = 0.001) and retraction size (p = 0.002) than the intact group. Retraction size (odds ratio [OR] = 3.053) and entropy (OR = 17.095) were significant predictors. Conclusion Texture analysis of torn SSTs on preoperative T2-weighted MRA using the GLCM may be helpful to predict postoperative tendon state after rotator cuff repair.

Factors Affecting Radiation Exposure during Lumbar Epidural Steroid Injection: A Prospective Study in 759 Patients

Objective To estimate and compare radiation exposure and intervention time during lumbar epidural steroid injection (ESI) 1) under different practitioners and methods with continuous fluoroscopic monitoring, and 2) under one practitioner with different methods and monitoring. Materials and Methods We consecutively recruited 804 patients who underwent lumbar ESI and 759 patients who underwent 922 interventions were included for analysis in this investigation. Three different practitioners (a senior faculty member, junior faculty member, trainee) performed lumbar ESI using different methods (caudal, interlaminar, transforaminal). The senior faculty member performed lumbar ESI under two different methods of fluoroscopic monitoring (continuous [CM] and intermittent monitoring [IM]). The dose area product (DAP) fluoroscopy time, and intervention time during lumbar ESI were compared for 1) ESI methods and practitioners under CM, and 2) ESI methods and monitoring. Results With CM, interaction between the effects of the practitioner and the intervention on DAP was significant (p < 0.001), but not fluoroscopy time (p = 0.672) or intervention time (p = 0.852). The significant main effects included the practitioner and intervention on DAP, fluoroscopy time, and intervention time with CM (p < 0.001). DAPs and fluoroscopy time for caudal, interlaminar, and transforaminal ESI were higher with CM than with IM (p < 0.001). Intervention time did not differ between CM and IM. Conclusion Radiation exposure is dependent on the practitioners and methods and within the established safety limits during lumbar ESIs under CM. With an experienced practitioner, IM leads to less radiation exposure than CM.

Intra-Articular Injections in Patients with Femoroacetabular Impingement: a Prospective, Randomized, Double-blind, Cross-over Study

We evaluated and compared the effectiveness of intra-articular injection of hip joint using hyaluronic acid and steroid in patients with femoroacetabular impingement (FAI). Thirty patients with FAI clinically and radiologically were enrolled and underwent hip injection using steroid (TA) or hyaluronic acid (HA) at 0-weeks with cross-over injection at 2-weeks in patients without clinical response of decrease of pain intensity less than 2-point. Patients were followed up to 12-weeks for pain intensity (Numeric rating scale, NRS: 0-10), hip disability score (HOOS), oral medication and adverse events. In 17 patients without cross-over, HOOS at 2-weeks was improved significantly in patients with HA injection (mean increase of HOOS = 13.8 with HA vs. -2.2 with TA, P = 0.031) without difference of NRS (P = 0.943). In 13 patients with cross-over, NRS was significantly improved at 2-weeks with first TA injection (mean decrease of NRS= 1.7 with first TA vs. 0.3 with first HA, P = 0.036), without difference of HOOS (P = 0.431). At 4-weeks, NRS and HOOS were significantly different according to injection drugs (NRS: 0.9 with TA first and HA later vs. 2.7 with HA first and TA later, P = 0.001; mean increase of HOOS: 5.3 with TA first and HA later vs. 10.2 with HA first and TA later, P = 0.032). Intra-articular hip injection may be effective in FAI, with faster effect of pain improvement by TA and more delayed effect of function improvement by HA.

An Osteochondral Lesion of the Distal Tibia and Fibula in Patients With an Osteochondral Lesion of the Talus on MRI: Prevalence, Location, and Concomitant Ligament and Tendon Injuries.

OBJECTIVE The purpose of this study was to evaluate the prevalence and common location of a coexisting osteochondral lesion of the distal tibia and fibula and of associated abnormalities of the ankle ligaments and tendons on MRI in patients with an osteochondral lesion of the talus (OLT). MATERIALS AND METHODS A search of a database of MRI studies performed between July 2003 and January 2014 yielded MRI examinations of 297 feet with OLTs. Two readers reviewed the MRI examinations independently for the presence of an osteochondral lesion of the distal tibia and fibula and for concomitant ligament and tendon injuries. If an osteochondral lesion of the distal tibia and fibula was present, the reviewers also recorded the location (zones 1-10) and stage. Interobserver and intraobserver reliabilities were assessed using kappa statistics. The associations between a coexisting osteochondral lesion of the distal tibia and fibula and an OLT or a concomitant ankle injury were evaluated using the chi-square test. RESULTS Readers A and B identified 61 (20.5%) and 47 (15.8%) coexisting osteochondral lesions of the distal tibia and fibula, respectively, with good interobserver (κ = 0.73) and excellent intraobserver (κ = 0.97) reliabilities. The most common location of a coexisting osteochondral lesion of the distal tibia and fibula was zone 4 (29.5%) by reader A and zone 2 (21.3%) by reader B. Stage I and stage IIA were common (> 85%). The frequency of osteochondral lesions of the distal tibia and fibula was not significantly different according to the location or stage of OLT. Abnormalities in the tibialis posterior tendon and in the anterior and posterior talofibular, calcaneofibular, and deltoid ligaments were significantly more common in patients with a coexisting osteochondral lesion of the distal tibia and fibula than in those with an isolated OLT (p < 0.05). CONCLUSION A coexisting osteochondral lesion of the distal tibia and fibula is not rare on MRI in patients with an OLT and is related to a higher frequency of concomitant ankle ligament and tendon injuries.